Steam set-works for sawmills.



No. 734,947. PATENTED JULY 28, 1903. DE WITT G. PRESCOTT. STEAM SET WORKS FOR SAWMILLS.

APPLICATION FILED APR. 3. 1903.

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DE WITT O. PRESCOTT. STEAM SET WORKS FOR SAWMILLS.

APPLIGATIONIILBD APR. a. 1903. N0 MODEL. 8 SHEETS-SHEET 2.

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No. 734,947. PATENTED JULY 28, 1903. DE WITT C. PRESCOTT. STEAM SET WORKS FOR SAWMILLS.

APPLIOATION FILED APR. 3, 1903.

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PATENT OFFICE.

STEAM SET-WORKS FOR SAWMILLS.

SPECIFICATION forming part of Letters Patent No. 734,947, dated July 28, 1903. Application filed April 3, 1903. Serial No. 150,879. (No model.)

Improvements in Steam Set-\Vorksfor Saw-' mills, of which the following is a specification and which are illustrated in the accompanying drawings, forming a part thereof.

This invention relates to improvements in sawmill set-works, and particularly to that type which is driven or operated by steam or other fluid underpressure.

One of the objects of the invention is to provide a steam set-works which shall be especially adapted to the handling of very large logs, to the setting of which the ordi nary steam set-works are not well adapted; and the invention also has for a furtherobject to generallyimprove and simplify the construction of the operative connection between the power mechanism and the logknees.

The invention consists of the combination and arrangement of parts hereinafter fully described, particularly designated in the claims, and illustrated in the accompanying drawings, in which- Figure 1 is a side elevation of a steam set-.

works constructedin accordance with my invention and showing the arrangement of the engine, retarding-cylinder, and adjustable stop for limiting the throw of the engine, the bearing for the set-shaft being removed.

Fig. 2 isa plan, on an enlarged scale, of the operative connection between the power mechanism and the log-knees. Fig. 3 is a rear elevation of the same; and'Fi'g. 4 is a section on the line A A of Fig. 3, the drivingratchet being removed.

Referring to Fig. 1, I have shown at 10 a base or bed having a back plate 11, upon which is mounted and secured asteam-cylinder 12, wherein reciprocates a piston (not shown) having connected thereto a forwardly-extending piston-rod 13, the engine being controlled by the usual Valve located in the chest 14. A cylinder 15, designed to contain oil or other fluid and having a piston therein connected to a reciprocating part of the engine 12, as to a rearward extension 16 of the piston-rod 13, is intended to retard the journaled on a shaft for communicating the motion to the knees and through the medium of pawls actuate a ratchet-wheel fixed to the said shaft and impart thereto a practically continuous rotary motion.

Referring more in detail to the structure, the rack-bar 19 engages a segmental gear 21,

(see Fig. 4,) loosely mounted on a shaft 22,

journaled in bearings, one of which, as 23, is supported from the base 10, while the other, or 24:, is located on the sawmill-carriage, as shown in Fig. 3. Fixed to the inner face of the segmental gear 21 is an arm 25, carrying one or more spring-pressed pawls 26, adapted to engage a ratchet-wheel 27, fixed to the shaft 22. Located at the opposite side of the ratchetwheel 27 from the pawlcarrier 25 and loose on the shaft 22 is a second pawlcarrier 28, also provided with spring-pressed pawls similar to 26, engaging the ratchetwheel, which is of sufficient width to avoid interference between the pawls when they pass during the oscillation of the carriers. The pawl carrier 28 is fixed to a segmental gear 29, which meshes with the lower rack bar 20. In the construction illustrated two pawls are mounted on each pawl-carrier and are differentiated from the spacing of the teeth of the ratchet, so'as to be non-synchronous in action in orderto provide for a finer adjustment, and pawl-lifters 30, which may be of any approved construction, may be provided for throwing the pawls out of engagement with the ratchet 27 when it is desired to recede the knees. The rack-bars 19 and 20 are held in engagement with the segmental gears by adjustable bars 31, seated in grooves formed in the base and back plate, as at 32, and adjusted by bolts33, passing through the bottom of the said grooves.

The range of movement of the engine-piston is limited by a stop consisting of a lever 34, pivoted to the base-plate and cooperating With a segmental ratchet 35 through the medium of a manually-controlled spring-pawl 36, which engages the said ratchet. The 1ever is disposed in such manner as to be in the path of the cross-head 18 and may, as is common in such machines, be set so as to regulate and vary at will the range of movement of the piston-rod, and consequently of the logknees.

The machine is preferably secured to the rear of the sawmill-carriage, as shown in Fig. 2, with the shaft 22 extending transversely of the latter, the said shaft then being provided with a screw 37 for moving one of the knees, as 38. Motion may be communicated to the screw-shafts driving the other knees of the carriage through the medium of a bevelpinion 39, fixed to the shaft 22 and communicating motion to a gear 40, fixed to a shaft 41, journaled on the carriage and longitudinally thereof.

A hand-wheel 4:2, fixed to the end of the shaft 22, provides means for setting by hand, if so desired.

In setting with a hand-lever set-works in which the knees are moved by screws a very limited movement is possible at each throw of the lever, owing to the limited range of movement of the latter. Under the present construction, however, a much wider range may be secured during a single reciprocation of the piston, thereby greatly expediting the setting operation.

I claim as my invention- 1. In a sawmill set-works, in combination, a reciprocating engine, a cross-head attached to the piston-rod thereof, a shaft, a ratchetwheel fixed thereto, a pair of gears located at opposite sides of the ratchet-wheel and loosely journaled on the shaft, a pawl carried by each of the gears and engaging the ratchetwheel, and rack-bars fixed to the cross-head, extending at opposite sides of the shaft and meshing with the gears.

' 2. In a sawmill set-works, in combination, areciprocating engine, a cross-head attached to the piston-rod thereof, means for retarding the speed of the engine, a shaft, a knee driven thereby, a ratchet-wheel fixed to the shaft, a

pair of gears located at oppositesides of the ratchet-wheel and loosely journaled on the shaft, pawls carried by the gears and actuating the ratchet in alternation, and rackbars fixed to the cross-head, extending at opposite sides of the shaft, and meshing with the gears.

3. In a steam set-works, in combination, a base, a reciprocating engine mounted on the base, an oil-cylinder for retarding the speed of the engine, a shaft, a ratchet-wheel fixed to the shaft, a cross-head attached to the piston-rod of the engine, racks projecting from the cross-head at opposite sides of the shaft, a pair of oppositely-oscillating gears located at opposite sides of the ratchet-wheel, loosely journaled on the shaftand meshing with the racks, pawls carried by the gears and coacting with the ratchet-wheel in alternation,bars seated on the base and on which the racks slide, and means for adjusting the bars.

4:. In a sawmill set-Works, in combination,

a reciprocating engine,a set-shaft, a log-knee, driving connection between the shaft and the knee, a ratchet-wheel fixed to the shaft, a pair of oppositely-oscillating gears loosely journaled on the shaft at opposite sides of the ratchet-wheel, a pawl carried by each gear and engaging the ratchet-wheel, rack-bars driven by the engine and actuating the gears, and an adjustable stop for limiting the movement of the engine.

5. In a sawmill set-works, in combination, a reciprocating engine, an oil-cylinder for retarding the speed of the engine, a log-knee, a shaft provided with a screw for driving the knee, connection from such shaft for driving the other knees, a ratchet-wheel fixed to the shaft, a pair of oppositely-oscillating gears loosely jourualed on the shaft at opposite sides of the ratchet-wheel, a pawl carried by each gear. and engaging the ratchet-wheel, a cross-head attached to the piston-rod of the engine, rack-bars projecting from the crosshead at opposite sides of the shaft and meshing with the gears, and an adjustable stop in the path of the cross-head.

DE VVITT C. PRESCOTT. Witnesses:

ARTHUR B. SEIBOLD, E. M. KLATCHER. 

